Cabinet, particularly for electrical installations

ABSTRACT

A cabinet, particularly for electrical switchboards and distributing plants, comprises a frame having vertical and horizontal supporting members, the vertical supporting members being formed by hollow section elements preferably consisting of lightweight metal. The transverse horizontal supporting members on the front and rear side of the frame are hollow section elements, and the longitudinal horizontal supporting members are formed by steel T-sections.

United States Patent Mayer et al.

1151 3,655,254 [451 Apr. 11,1972

1541 CABINET, PARTICULARLY FOR ELECTRICAL INSTALLATIONS [72] Inventors: Georg Mayer; Egon Glaser, both of Aargau, Switzerland [73] Assignee: Sprecher 81 Schuh, Aarau, Switzerland [22] Filed: Nov. 19, 1969 [21] Appl. No.: 878,171

[30] Foreign Application Priority Data Nov. 20, 1968 Switzerland .17384/68 [52] US. Cl ..312/257 [51] Int. Cl ..A47b 43/00, A47b 47/00 [58] Field ofSearch ..312/257;211/148, 177, 182

[56] References Cited UNITED STATES PATENTS 2,884,296 4/1959 Meilinger et al ..312/111 X 3,222,116 12/1965 Levenberg ..312/1ll X 3,302,799 2/1967 Blodet ..312/1 11 X 3,329,473 7/1967 Dickson ..312/111 X 2,105,868 1/1938 Thomas ..2l1/148 X 3,110,535 11/1963 Anderson 312/257 SK 3,150,903 9/1964 Chapman et al. 312/257 SK 3,178,246 4/1965 Riles ..3 12/257 SL 3,360,320 12/1967 Lust ..312/257 3,497,279 2/1970 Chovanec ..312/257 FOREIGN PATENTS OR APPLICATIONS 628,858 2/1963 Belgium ..312/111 Primary Examiner-Paul R. Gilliam ArtorneyWaters, Roditi, Schwartz & Nissen [57] ABSTRACT A cabinet, particularly for electrical switchboards and distributing plants, comprises a frame having vertical and horizontal supporting members, the vertical supporting members being formed by hollow section elements preferably con sisting of lightweight metal. The transverse horizontal supporting members on the front and rear side of the frame are hollow section elements, and the longitudinal horizontal supporting members are formed by steel T-sections.

6 Claims, 8 Drawing Figures Patented April 11, 1972 8 Sheets-Sheet 2 Fig 2 Patented April 11, 1972 3,655,254

8 Sheets-Sheet :3

Patented April 11, 1972 3,655,254

8 Sheets-Sheet 4 Fig 4 Patented April 11, 1972 8 Sheets-Sheet 5 Fig.5

Patented April 11, 1972 3,655,254

I a Sheets-Sheet e v 2 r I I 4 Patented April 11, 1972 8 Sheets-Sheet 7 Patented April 11, 1972 3,655,254

8 Sheets-Sheet 8 CABINET, PARTICULARLY FOR ELECTRICAL INSTALLATIONS The present invention relates to a cabinet, particularly for electrical installations.

Such cabinets serve mainly for accommodating electrical switchboards and distributing plants. They consist of a carrying frame with supporting elements for securing built-in units, as well as of lining walls, doors, lids, etc.

Such a cabinet may for example be executed in welded construction, a frame composed of welded angle sections carrying screwed-on encasing sheets forming a closed box provided with internal auxiliary supports to which the switching and/or distributing elements are anchored at the appropriate locations by means of screws or other fixing elements. The fittings for doors, lids, slide-in units and the like are provided as required and, according to the available workshop facilities, are fixed to the carrying frame by welding, riveting, screwing or the like. In order to be able to change the position of the built-in units, elongated holes are usually provided which, however, do not permit a stepless change in position. Such constructions are expensive in the case of small scale production; they are moreover not very adaptable to subsequent changes and are also esthetically unsatisfactory. Since they are varnished before the built-in units are assembled, the layer of varnish or paint is usually damaged during assembly and a subsequent coating is' again necessary in order to avoid the formation of rust.

A further known embodiment consists of sheet metal with integral carrying sections produced by bending the sheets, and of reinforcements. These sheets are connected by welding, screwing or the like. Their drawback consists in the lacking of adaptability to the external shape.

Recently cabinets with a carrying frame composed of lightweight metal sections are proving successful, the sections being screwed to one another by means of corner brackets.

For accommodating different built-in units, longitudinal sup- 7 ports, cross supports or like holding elements are screwed to the carrying frame. The connection of the individual profiled bars and sections requires skilled labor and is correspondingly expensive, particularly when additional built-in units are to be inserted later.

In summary, it may be said for the above-mentioned known types of construction, that their production requires a high expenditure of work and tools and above all they cannot be adapted to different built-in units without requiring additional work. As has already been mentioned, a further drawback of the constructions composed of steel is the fact that the layer of paint may be damaged during assembly.

In another known cabinet for electrical installations, clamping means are provided for the stepless adjustment of the position of the cross and longitudinal supports for the installations in the carrying frame. However, the clamping joints used for this purpose has the considerable drawback that they only result in a poor connection. The clamped elements are held together exclusively by friction contact. Upon application of extraordinary loads, mainly during transport, vibrations and unsatisfactory assembly, individual elements may become detached, there is the danger of distortion of the cabinet and the holding together of the construction may be endangered.

The present invention has for its object the provision of a cabinet for electrical installations, wherein the above-mentioned drawbacks are avoided. The cabinet construction according to the invention is able to be produced from a small number of different sections, with great accuracy to gauge, with low working expenditure even in the case of small scale and single piece production and simple tools only are required for assembling the components. Furthermore, a stepless displacement of the position of the individual carrying and fixing elements is possible for the built-in units, also at a later stage when the cabinet is already in use. A subsequent finishing treatment of the individual elements is not necessary and larger plants can be assembled by a plurality of individual cabinets which can be joined economically, pleasingly and technically satisfactorily.

The cabinet according to the invention comprises a carrying frame having vertical and horizontal supporting elements, said vertical supporting elements being fonned by hollow section rods having their outer contour provided with a plurality of outwardly open recesses adapted to receive supporting and encasing elements, fittings, sealing means and fixing means for said horizontal supporting elements, said horizontal supporting elements at the front and rear side of the frame being hollow section rods each having a threaded bore for receiving a screw connecting said vertical hollow section rods with said horizontal hollow section rods.

A preferred embodiment of a cabinet according to the invention will now be described with reference to the accompanying drawings, in which,

FIG. v1 is a perspective view of the carrying frame of the cabinet according to the invention,

FIG. 2 is a cross section of a vertical supporting section of the frame,

FIG. 3 is a perspective view of the connecting means for fixing a vertical supporting section to a head support,

FIG. 4 is a perspective view, partly drawn in section of the manner of assembling a vertical supporting sertion with a horizontal bottom support,

FIG. 5 is a perspective view of two vertical supporting sections and their connection to an upper side carrier element,

FIG. 6 is a perspective view of a vertical supporting section having a lining element fixed thereto, and

FIGS. 7 and 8 show the manner of fixing of various fittings and connecting elements to a vertical supporting section.

The carrying frame of a cabinet for electrical installations, shown in FIG. 1, has four vertical supporting elements or sections 1, which form the vertical boundary edges of a cabinet. These vertical sections are connected together at the top and bottom by two head supports 2 and bottom supports 3 on the front and rear sides of the frame, and by a total of four side members 4 on the two longitudinal sides of the frame.

FIG. 2 shows a cross-section through a vertical element 1. This element is a hollow lightweight metal extruded section having an outer contour with a plurality of reentrants or outwardly open recesses 6,7,8. 11 and 12. The parts of the section 1 surrounding the cavity 5 has two grooves 6 and 7 which serve to receive corresponding convex parts of covering and fixing elements or fittings, described hereinbelow. Between the two grooves 6 and 7 is located another groove 8 into which a packing strip may be inserted, when two cabinets are to be connected together on this side of the section 1 or when a cabinet abuts against any other surface.

On the opposite side of the section 1 is located an open channel-shaped section 9, which, as will be explained later, may receive nuts for fixing the side members 4. The outer face 10 of the channel section 9 is provided with a groove 11 preferably for receiving a sealing strip 11, as well as with a rabbet 12 for receiving an edge of a metal sheet of a lining element 12'.

FIG. 3 shows the means for connecting a vertical section 1 to a head support 2. The latter also is formed by a hollow extruded section of lightweight metal, preferably an aluminum alloy, and is provided with a substantially pentagonal, prismatic cavity 13 as well as with two bores 14 of circular cross section, and further with a U-shaped flange or ledge 15 on the underside. The outer surface 16 is plane; two further plane faces 17 and 18 form the upper closure of the section.

For connecting the head support 2 to the vertical section 1, the head support is cut out on its end face as shown at 2' in FIG. 3. The depth of the cut-out portion corresponds in the longitudinal direction of the section 2 to the width of the vertical section 1 in this direction; transversely hereto, the cut-out is so deep that the axes of the bores 14 of the head support are situated in the center of the substantially square part of the vertical section 1. A filler plug 19 of square cross-section having chamfered longitudinal edges and a continuous longitudinal bore 20 is located in the cavity 5 of the vertical section, a screw thread 21 being cut into the upper part of the bore 20 for receiving an eye bolt for transporting the frame. Moreover,

the filler plug 19 is provided with two transverse bores 22, the lower one of which is visible in FIG. 3 in the lower pm of the plug 19 which has been shown in section. The axes of the transverse bores 22 coincide with those of the bores 14 in the head support 2. Two screws 23 having an internally hexagonal screwhead connect the vertical section 1 with the head support 2, to which end a corresponding thread 24 is cut in the bores 14. The bore 22 is countersunk at its outer end and has a somewhat larger diameter than the diameter of the circular head of the screw 23, the head of the screw when tightened being flush with the outer face of the vertical section.

In similar manner the vertical sections are connected to the ends of the bottom supports 3. FIG. 4 shows such a connection. The support 3 is also an extruded hollow section of light metal, having a cavity 25 and two longitudinal bores 26 of circular cross section. On the upper side of the support 3 is located a U-shaped flange 27, and the underside is provided with a shallow rabbet 28 adapted to engage over an adjoining floor covering 29. The connection of the support 3 to the vertical section 1 is effected, like the top supports, by means of two screws 30 having an internally hexagonal head, but without the intermediary of a filling plug, since the lower connection is only comparatively slightly loaded. The upper connection must, on the other hand, take up the entire share of the weight acting on a vertical section, thus a quarter of the weight in the case of four sections and four eyebolts thereon.

The screws 30 are inserted through bores 31 in the outer face of the vertical section 1.

The connection of the side supports 4 with the vertical sections is illustrated in FIG. 5. The side supports consist of commercially available rolled or bent steel U-sections. Each end of a U-section is provided at both ends with a bore 32 and with two guide lugs 33 and 34, formed by cutting out and outwardly bending two tongues engaging the longitudinal slots 35 in the vertical sections 1. The bores 32 receive screws 36 with an internally hexagonal head and washers 37, which screws are screwed into threaded nut plates 38 engaged in the channel section 9 (see also FIG. 2) and thus press the side supports 4 firmly against the vertical sections 1. The nut plates 38 may be inserted from the upper open end of the channel section 9, but more advantageously through one of a plurality of lateral slots 39, namely through that slot situated next to the point of fastening provided for the side members of other carrying elements or fittings intended for receiving built-in units.

FIG. 6 shows how a panel element serving for encasing can be connected to the vertical sections 1. The panel element is an extruded profiled web 40 of light metal, preferably an aluminum alloy. This profiled web can be part of a front structure projecting forwardly from the front plane of the frame, for receiving indicating instruments or actuating and switching means. The cabinet may thus be lined above and below the front structure with decorative panels.

At the point of connection, the profiled web 40 has a groove 41, a projecting ledge 42 and an angle web 43. The projecting ledge 42 engages in the groove 6 of the vertical section 1, on the rear side of which a profiled plate 44 having a projecting ledge 45 engages in the second longitudinal groove 7 of the vertical section 1. The upper part of the profiled plate 44 is thickened and offset and has a groove 46 for receiving a metal sheet, a plate, a sealing member etc. according to the actual requirements. Screws 47 with washers 48 serve to fix the profiled web 40 to the upright. The screws are inserted in the profiled plate 44 through holes 48a and are screwed into threaded holes (not shown) in the profiled web 40, whereby the profiled web 40 and the profiled plate 44 are clamped fast to the vertical section 1.

FIG. 7 shows the fastening to vertical section 1 of a hinge part 49 for a door. Such a hinge part is cut to size from a hollow extruded section composed of an aluminum alloy and is clamped to the upright in the same manner as the profiled web 40 shown in FIG. 6 by means of the profiled plate 44 and screws 47. A T-shaped sealing strip 50 is inserted in the groove of the profiled plate 44, against which strip the face of the 4 door, not shown, can sealingly abut. The hinge part 49 comprises a flange 56 having a hook-shaped end portion 57 engaging the groove 6 of the vertical section 1.

Further examples of fastening possibilities at the front or rear side of a cabinet are shown in FIG. 8. Fittings 51 and 52 consist of a section having resilient clamping wings 53 and 58 terminating in hooks 59 and 60 to engage in open recesses 7 and 6 and which has the function of the profiled plate 44 in the embodiments according to FIGS. 6 and 7. For clamping purposes, the wing 53 is braced with the screws 47 against the left hand part of the section.

The lower fitting 52 is provided with a notch 54 and a threaded hole 55 for the purpose of fixing any built-in unit; the upper fitting 51 is again formed by a hinge part fixed to the frame.

Cabinets or cells produced according to the mode of construction described may not only be used individually but any desired number thereof may be combined with one another. In the first case, the side walls and possibly also the rear wall will be encased by panels or the like. When assembling together plants consisting of a plurality of cabinets, the meeting side walls do not need to be encased, but may be connected while directly joining each other. To this end, for example, as may be seen from FIGS. 3 and 4, circular notches 57 and bores 58 for screw nuts are distributed over the length of the vertical section 1, by means of which the cells can be connected to larger units. For sealing or for absorbing vibrations, elastic sealing strips inserted in the groove 11 of the vertical section (see FIG. 2) are advantageously used which strips prevent a metallic contact between the joined cabinets. The mentioned U-shaped webs 15 of the head supports 2 and 27 of the foot supports 3 may serve as supports for the edges of lining panels or the like, if desired with the interposition of a sealing strip in the groove of these webs.

The described constructional elements ideally fulfill the requirements mentioned at the beginning of the specification. With only a few types or profiles or light metal sections, there are many possibilities of configuration and combinations, the dimensions of the individual cabinets being practically freely selectable and the cabinet space may be subdivided as desired. Storage is simplified, as well as the expenditure for tools. Since the most important elements consist of lightweight metal, varnishing is as a rule superfluous and other surface preserving means, such as anodic treatment, are generally only necessary when using the cabinets in chemical plants.

We claim:

1. A cabinet for electrical installations, said cabinet comprising a carrying frame having front, rear and lateral sides, and including hollow profiled horizontal and vertical supporting elements, said vertical supporting elements each including a laterally projecting channel portion extending the length of the vertical element, the channel portions of two vertical supporting elements at the front and rear sides of the frame facing one another and extending at the lateral sides of the frame, said horizontal supporting elements being hollow profiled members extending at the front and rear sides of the frame between two vertical supporting elements and including threaded bores extending lengthwise thereof, screw members introduced through holes provided in said vertical supporting elements and engaged in said bores for fixing the horizontal supporting elements at the front and rear sides of said frame to the vertical supporting elements, said carrying frame further including side supports at the lateral sides of the frame fixed to the laterally projecting channel members facing each other of a front and rear vertical supporting element.

2. A cabinet according to claim 1, in which said horizontal and vertical profiled hollow supporting elements are extruded lightweight metal sections.

3. A cabinet according to claim 1, in which said vertical supporting elements each includes a portion having a closed cavity and outwardly open grooves for fixing encasing elements, fittings, and sealing means.

4. A cabinet according to claim 3, comprising a reinforcement plug inserted into said cavity at the upper end of each said vertical supporting element, said screw members passing through said reinforcement plugs.

5. A cabinet according to claim 4, in which the side supports at the lateral sides of the frame are constituted as U-shaped rails with two branches of the U-section to the channel members of the vertical supporting elements, said web being provided with tongues at both sides of said holes, said tongues being bent out of the plane of the web to slidingly engage into said channel portions, said vertical supporting elements being provided with slots for inserting nut plates into the channel 

1. A cabinet for electrical installations, said cabinet comprising a carrying frame having front, rear and lateral sides, and including hollow profiled horizontal and vertical supporting elements, said vertical supporting elements each including a laterally projecting channel portion extending the length of the vertical element, the channel portions of two vertical supporting elements at the front and rear sides of the frame facing one another and extending at the lateral sides of the frame, said horizontal supporting elements being hollow profiled members extending at the front and rear sides of the frame between two vertical supporting elements and including threaded bores extending lengthwise thereof, screw members introduced through holes provided in said vertical supporting elements and engaged in said bores for fixing the horizontal supporting elements at the front and rear sides of said frame to the vertical supporting elements, said carrying frame further including side supports at the lateral sides of the frame fixed to the laterally projecting channel members facing each other of a front and rear vertical supporting element.
 2. A cabinet according to claim 1, in which said horizontal and vertical profiled hollow supporting elements are extruded lightweight metal sections.
 3. A cabinet according to claim 1, in which said vertical supporting elements each includes a portion having a closed cavity and outwardly open grooves for fixing encasing elements, fittings, and sealing means.
 4. A cabinet according to claim 3, comprising a reinforcement plug inserted into said cavity at the upper end of each said vertical supporting element, said screw members passing through said reinforcement plugs.
 5. A cabinet according to claim 4, in which the side supports at the lateral sides of the frame are constituted as U-shaped rails with two branches of the U-section to the channel members of the vertical supporting elements, said web being provided with tongues at both sides of said holes, said tongues being bent out of the plane of the web to slidingly engage into said channel portions, said vertical supporting elements being provided with slots for inserting nut plates into the channel members for cooperating with fixing screws inserted through said holes.
 6. A cabinet according to claim 5, comprising extruded encasing sections and fittings having a web with a hook-shaped end portion engaging into one of said outwardly open recesses of the vertical supporting elements, and profiled plates having a hook-shaped longitudinal edge engaging into another one of said outwardly open recesses of the vertical supporting elements, said profiled plates and said encasing elements and fittings being braced by screws. 